Hitachi VM-SP1A - Page 26

::CHARGING THE BATTERY
9. Do not attempt to disassemble or modify the battery. There are no user serviceable parts
inside.
10. Throwing the battery into a fire or exposing the battery to excessive heat - over 149°F
(65°C) could be hazardous.
11. Set the mark switch of any battery which has already been charged to red as shown in
the figure. This lets you discriminate between charged and uncharged batteries easily.